Process for fixing dyes in textile materials

Abstract

A process for fixing dyes impregnated in fine-dimensional synthetic textile substrates in an environmentally safe manner. The process comprises contacting the dyed synthetic substrates with a phenol- and formaldehyde-free dye-fixative composition comprising: (a) polymethacrylic acid, (b) copolymers of methacrylic acid consisting essentially of methacrylic acid and an ethylenically unsaturated comonomer selected from the group consisting of 2-acrylamido-2-methyl-propanesulfonic acid, sodium vinyl sulfonate, sodium styrene sulfonate, alkyl acrylate, and combinations thereof, (c) combinations of (a) and (b), and (d) water.

What is claimed is: 
     
       1. A process for fixing a dye to a dyed fine-dimensional yarn fabric made from the group consisting of a polyamide-containing substrate, segmented polyester-polyurethane substrate, and combinations thereof, comprising contacting said fabric with an aqueous solution comprising a dye-fixative composition substantially free of phenol and formaldehyde residues, said dye-fixative composition being elected from the group consisting of (a) polymethacrylic acid, and   (b) a copolymer of methacrylic acid and an ethylenically unsaturated comonomer selected from the group consisting of 2-acrylamido-2-methyl-propanesulfonic acid, sodium vinyl sulfonate, sodium styrene sulfonate, lower alkyl acrylates, and combinations thereof,   said contacting step being for a time sufficient so that said dye-fixative composition is absorbed by said fabric.   
     
     
       2. The process of claim 1 wherein said dye fixative composition contains at least about 30% by weight methacrylic acid, based on the weight of said dye-fixative composition. 
     
     
       3. The process of claim 1 wherein said comonomer of said copolymer of methacrylic acid comprises 2-acrylamido-2methyl-propanesulfonic acid. 
     
     
       4. The process of claim 3 wherein said copolymer of methacrylic acid contains at least about 10% by weight of said 2-acrylamido-2-methyl-propanesulfonic acid, based on the weight of said copolymer. 
     
     
       5. The process of claim 1 wherein said comonomer of said copolymer of methacrylic acid comprises sodium vinyl sulfonate. 
     
     
       6. The process of claim 5 wherein said copolymer of methacrylic acid contains at least about 1% by weight of said sodium vinyl sulfonate, based on the weight of said copolymer. 
     
     
       7. The process of claim 1 wherein said comonomer of said copolymer of methacrylic acid comprises sodium styrene sulfonate. 
     
     
       8. The process of claim 7 wherein said copolymer of methacrylic acid contains at least about 10% by weight of said sodium styrene sulfonate, based on the weight of said copolymer. 
     
     
       9. The process of claim 1 wherein said comonomer of said copolymer of methacrylic acid is a lower alkyl acrylate having from 1 to 4 carbon atoms. 
     
     
       10. The process of claim 9 wherein said copolymer of methacrylic acid contains at least about 5% by weight of said lower alkyl acrylate, based on the weight of said copolymer. 
     
     
       11. The process of claim 1 wherein said dye-fixative composition is present in an amount of at least about 1% by weight, based on the weight of said fabric. 
     
     
       12. The process of claim 1 wherein said dye-fixative composition has a weight average molecular weight of from about 2000 to about 250,000. 
     
     
       13. The process of claim 1 wherein said dye-fixative composition has a number average molecular weight of from about 500 to about 20,000. 
     
     
       14. The process of claim 1 wherein said polyamide-containing substrate comprises nylon 6 fiber. 
     
     
       15. The process of claim 1 wherein said polyamide-containing substrate comprises nylon 6,6 fiber. 
     
     
       16. The process of claim 1 wherein said segmented polyester-polyurethane substrate comprises lycra or spandex. 
     
     
       17. The process of claim 1 wherein said fine-dimensional yarn fabric consists essentially of knit and woven apparel fabric. 
     
     
       18. The process of claim 1 wherein said dye-fixative composition has a pH from about 4.0 to about 7.0. 
     
     
       19. The process of claim 1 wherein said dye-fixative composition provides to said substrate a colorfastness value of at least about 4.0 obtained according to AATCC Test Method 107. 
     
     
       20. The process of claim 1 wherein said dye-fixative composition provides to said substrate a stain resistance value of less than 5 obtained according to AATCC Test Method 175-1993. 
     
     
       21. The process of claim 1 wherein said dye-fixative composition is applied to said fabric in an amount of from about 2 to about 8 percent by weight, based on the weight of said fabric. 
     
     
       22. The process of claim 1 wherein said yarn fabric is selected from the group consisting of knit and woven apparel fabric. 
     
     
       23. The process of claim 1 wherein said fabric is contacted with said dye-fixative composition in an amount effective to fix said dye to said fabric. 
     
     
       24. The process of claim 1 wherein said fabric is contacted with said dye-fixative composition at a pH between about 4.0 and about 5.0. 
     
     
       25. The process of claim 1 wherein said fabric is contacted with said dye-fixative composition at a temperature of between about 140° F. and 180° F. 
     
     
       26. A fine-dimensional yarn fabric made from the group consisting of a polyamide-containing substrate, a segmented polyester-polyurethane substrate, and combinations thereof treated with a dye and an aqueous dye-fixative composition selected from the group consisting of polymethacrylic acid, copolymers of methacrylic acid, and combinations thereof, said copolymers of methacrylic acid comprising at least about 30 weight percent methacrylic acid and said polymethacrylic acid, copolymers of methacrylic acid, or combinations thereof having the lower 90 weight percent having a weight average molecular weight in the range of about 2500 to 250,000 and a number average molecular weight in the range of about 500 to 20,000 and being provided in a sufficient amount and having a solubility such that said dye is fixed to said substrate, said substrate having a colorfastness value of at least about 4.0 obtained according to AATCC Test Method 107-1991, and a stain resistance value of less than 5 obtained according to AATCC Test Method 175-1993.